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Updated: Oct 1, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Chiral fluoro ketones for catalytic asymmetric epoxidation of alkenes with oxone
Scott E Denmark1, Hayao Matsuhashi
1Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801, USA. denmark@scs.uiuc.edu
Abstract:
Two structurally dissimilar, chiral fluoro ketones have been prepared and their potential as enantioselective catalysts for asymmetric epoxidation with Oxone has been evaluated. The tropinone-based ketone (-)-5 was easily prepared and showed excellent reactivity but only modest enantioselectivity. The biphenyl-based ketone (-)-6 was prepared in a somewhat lengthy synthesis (along with its monofluoro and geminal fluoro analogues). This ketone exhibited only modest reactivity; 30 mol % of (-)-6 was needed to bring about complete conversion in a reasonable time. The enantioselectivity of this catalyst was generally much higher, but again very substrate dependent.
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